A Waterproof Cast Liner Earns High Marks
Harlan Selesnick, MD; Geoffrey Griffiths, MD
THE PHYSICIAN AND SPORTSMEDICINE - VOL 25 - NO. 9 - SEPTEMBER 97
In Brief: Nondisplaced and stable fractures or severe sprains may be casted using fiberglass and a waterproof liner. Application of the liner is illustrated and described here. Allergic reactions, liner bulkiness, cast application and removal, and cost of materials have not proven to be problems. Among 337 patients fitted with this liner, odor, itching, and difficulties with drying were minimal, even though patients swam, bathed, or received hydrotherapy. Minor skin complications occurred in 5.9% of patients. Physician and patient satisfaction with the liner was high.
Although recent advances in orthopedics, such as functional bracing and rigid internal fixation, have decreased the need for cast immobilization, many patients still require casts for treatment of injuries. A fiberglass cast with a waterproof liner that "breathes" is a treatment option for patients who have nondisplaced or stable fractures or severe sprains. Our initial experience in using the waterproof liner with 140 patients, reported in these pages in 1993 (1), indicated that it allows patients to maintain a more normal lifestyle than is possible with traditional casts.
Our subsequent use of the waterproof liner with nearly 200 more patients has corroborated the earlier findings. Details of our 7-year study of the liner are reported separately (see, "Physicians and Patients Rate Waterproof Liner," below); the main text addresses practical questions regarding use of the liner.
Traditional vs Waterproof Casts
Traditional cast construction, using plaster of paris or fiberglass, often results in cutaneous complications (1-15), including macerations, ulceration, infections, burns, blisters, rashes, and allergic contact dermatitis. Patients report that such casts itch, smell, and are difficult to keep dry (4). Plaster of paris casts break down if patients get them wet. Although fiberglass casts with stockinette and cast padding can withstand moisture, they must be dried, perhaps with a hair dryer, to minimize cutaneous complications. Maceration, odor, and itching frequently develop when damp areas remain beneath the fiberglass cast (1-3,9,11,12,15).
Waterproof cast construction uses a waterproof cast liner made of Gore-Tex (W. L. Gore and Associates, Inc, Flagstaff, Arizona) to replace the traditional stockinette and cast padding (1,12,13). The Gore-Tex liner repels water and permits evaporation, allowing bathing, swimming, sweating, and hydrotherapy without any special drying of the cast or skin (1,12,16). The liner material is available in rolls of 2-, 3-, and 4-in. width (figure 1) and is applied directly to the patient's skin (figures 2-4). Fiberglass casting tape is then wrapped around the waterproof liner (figure 5).
Questions and Answers
Given the high degree of satisfaction among patients and physicians (See "Physicians and Patients Rate Waterproof Liner," below), waterproof liners clearly provide an attractive treatment option for many fractures and sprains. Below are answers to common questions about the liners.
What are the accepted indications for the waterproof liner? As a general rule, the waterproof liner has the same indications as a traditional fiberglass cast. In our study, the waterproof liner was used for nondisplaced and stable fractures and severe sprains. Patients with fractures that had been previously reduced with plaster of paris casts and were subsequently stable enough for conversion to a fiberglass cast were also used in the study.
Are many patients allergic to the waterproof liner? None of the 337 patients in our study had allergic reactions to the liner.
Is the waterproof liner bulky and difficult to apply? The waterproof liner is slightly more difficult to apply than traditional liners, but a series of a few casts will make the practitioner feel comfortable with the process. The liner makes the cast a little thicker, but few patients complain.
Can patients be burned during application when the fiberglass heats after being dipped in water? None of our patients was burned during cast application. We recommend that the cast liner be at least two layers thick over the skin and three layers thick over bony prominences. The fiberglass should be dipped in cold water during cast application to minimize the risk of complications.
Are patients with a waterproof liner more likely to be cut with the cast saw during cast removal? The liner should be applied evenly and appropriately thick during casting. Proper care during cast removal will minimize the risk of lacerations. In our study, only one minor skin laceration occurred during removal.
Isn't the cost prohibitive? At the time of our study, the average cost to physicians for the waterproof cast liner was about $20 more for a short arm cast and $30 more for a short leg cast than for fiberglass versions using the traditional stockinette and cast padding. Many insurance companies will reimburse physicians for the waterproof liners, and many patients (except for those who are not allowed because of Medicare or health maintenance organization regulations) are more than willing to pay the additional cost for the convenience of the waterproof cast. Furthermore, cast changes appear to be less frequent with waterproof casts because they usually stay comfortable throughout the immobili-
Are there any other disadvantages? Since the fiberglass over the waterproof liner is hard and may cause injury to others, appropriate padding must be placed over the cast if an athlete is allowed to compete during immobilization.
A fiberglass cast lined with a waterproof material, though, is comfortable and useful for active people such as athletes, outdoor workers, and children. Maintaining activity, cleanliness, and skin health while wearing a cast contributes to the high degree of patient and physician satisfaction with this alternative.
Physicians and Patients Rate Waterproof Liner
Three hundred thirty-seven patients in our practice were fitted with waterproof liners and fiberglass casts between May 1, 1990, and March 6, 1997. The series included all patients who had nondisplaced and stable fractures or severe sprains, along with patients whose fractures had been previously reduced with plaster of paris casts and were subsequently stable enough for a fiberglass cast. The patients' age range was 3 to 92 years (mean, 30.3 years). There were 207 male and 130 female patients, and 7 had insulin-dependent diabetes. The types of casts applied are listed in table A.
After each cast application, the patient's gender, age, type of injury, type of cast, and history of allergies or diabetes were recorded, as were the cast's ease of application and the size and number of cast liner rolls used. After cast removal, both patient and physician completed satisfaction and performance surveys obtained from the liner manufacturer. (These scales are being used at multiple institutions. In addition to the authors, three other physicians completed performance surveys.)
Itching was minimal or not a problem for 81.7% of the patients; 14.4% reported that itching was acceptable, and 3.9% that itching was a problem. Skin irritation was not a problem. Odor was a problem for 6.6% of patients. Comfort and fit were good or exceptionally good for 86% of the patients.
Of 313 patients who intentionally got their casts wet, only 6.6% felt that the drying time was too long; most (80.3%) did not try to accelerate cast drying. Drying of the cast averaged less than 30 minutes for 32.4% of patients, 31 to 60 minutes for 41%, 1 to 2 hours for 21.6%, and more than 2 hours for 5%. The patients bathed an average of 7.1 times per week. Swimming was a regular activity for 139 patients, who swam an average of 3.8 times per week. Seven patients had hydrotherapy an average of 5.6 times per week.
One hundred fifty-one patients had worn traditional casts before this study, while 186 patients had never worn a cast. The two groups' survey responses were almost identical in regard to odor, itching, comfort, drying time, and overall patient satisfaction. Three hundred thirty-five patients (99.4%) reported that they would recommend the waterproof liner to other patients.
Physicians' overall ratings of cast performance are shown in table B. At the time of application, 327 casts were rated easy or very easy to apply. Ten were mildly difficult to apply because of liner slippage or conforming difficulties. All fractures healed without complications.
On cast removal, skin condition was good or exceptionally good in 96.9% of the patients and fair in 3.1% patients. Two patients had mild skin blistering, 2 had a mild rash, and 3 had a small (less than 1 cm) superficial skin ulcer. None of the patients developed maceration, fungal infections, or bacterial infections. Fourteen patients had mild erythema that required no treatment; 323 patients had no erythema. There appeared to be no allergic reactions to the waterproof cast liner. Two patients required minor dermatologic care after casting. Skin problems did not appear related to the length of time the cast was worn.
One patient sustained a superficial 2-cm laceration during cast removal that healed without sequelae. Mild odor was noticeable on cast removal in 41 patients; the remaining 296 patients had no significant cast odor.
Dr Selesnick is an assistant clinical professor in the Department of Orthopedic Surgery and Sports Medicine at the University of Miami and the team physician for the Miami Heat of the National Basketball Association, Miami Jai Alai, and Dania Jai Alai. Dr Griffiths is an orthopedic surgeon at Kaiser Permanente Medical Center in Riverside, California. Address correspondence to Harlan Selesnick, MD, 6262 Sunset Dr, Suite 503, Miami, FL 33143.
Copyright (C) 1997. The McGraw-Hill Companies. All Rights Reserved